The correct view is that it is permissible for a blind man to lead the prayer and it is not disliked, because Prophet Muhammad appointed Ibn Umm Maktum to lead the prayer.

There is nothing wrong with Muslims praying in a church if it is free of images and statues, whether that is the Jumu`ah prayer or any other prayer. It is disliked for Muslims to pray in a church if there are images or statues in it.